Hydraulic Adapter Finder
Select the fitting standard and size on each side of your connection. This tool shows the adapter type, seal method, pressure rating, and installation guidance for your specific combination.
Find Your Adapter
Select the fitting standard and size on each side. The tool will show you what adapter you need, how it seals, and what to watch for during installation.
Reference data only. Verify thread dimensions with a thread identification gauge before making connections. Working with pressurized hydraulic systems involves serious injury risks including high-pressure injection, burns, and crushing hazards. This site does not replace manufacturer specifications, proper training, or employer safety procedures. See full terms of use.
Adapter Reference by Standard Pair
The table below lists common adapter configurations between hydraulic fitting standards. Each pair includes seal method, installation notes, and common mistakes. For uncommon combinations not listed here, chaining through JIC is usually the most available option.
JIC to NPT
Available sizes: -4, -6, -8, -10, -12, -16
Shapes: straight, 90-degree, 45-degree, bulkhead
Seal: JIC side seals metal-to-metal at the 37-degree flare. NPT side seals on the taper with PTFE tape or pipe compound. Do NOT put tape on the JIC side.
Installation: NPT side can crack cast aluminum or iron housings if over-tightened. Use a backup wrench on the port body.
Pressure: Assembly pressure rating is limited by the NPT side. NPT ratings drop significantly above -12 sizes.
Common mistake: Applying PTFE tape to the JIC flare nut. Only the NPT threads get tape. Tape on JIC prevents proper metal-to-metal seal.
JIC to BSP
Available sizes: -4, -6, -8, -10, -12, -16
Shapes: straight, 90-degree
Seal: JIC side: 37-degree flare, no sealant. BSP parallel side: requires bonded seal (Dowty washer). BSP taper side: requires PTFE tape. Identify whether the port is BSPP or BSPT before selecting adapter.
Installation: BSPP and BSPT ports look identical but require different adapters. Thread a fitting in by hand: if it bottoms out on a flat surface, it's parallel. If it wedges tighter as you turn, it's taper.
Pressure: Pressure rating depends on BSP variant. BSPP with bonded seal is comparable to JIC. BSPT with tape is comparable to NPT.
Common mistake: Confusing BSPP and BSPT. Using a taper adapter in a parallel port (or vice versa) will either leak immediately or strip the threads.
JIC to ORFS
Available sizes: -4, -6, -8, -10, -12, -16
Shapes: straight, 90-degree, 45-degree
Seal: JIC side: 37-degree flare. ORFS side: O-ring face seal. Both are reusable and sealant-free. This is a premium combination with excellent leak resistance.
Installation: Ensure the ORFS O-ring is properly seated in the groove before threading. A pinched O-ring fails immediately under pressure.
Pressure: Both standards have high pressure ratings. The assembly rating matches the lower of the two at the given size.
Common mistake: Reusing a damaged or extruded ORFS O-ring. Replace the O-ring every time you disassemble the connection.
JIC to SAE ORB
Available sizes: -4, -6, -8, -10, -12, -16
Shapes: straight, 90-degree, 45-degree
Seal: JIC side: 37-degree flare. SAE ORB side: O-ring boss. Both are sealant-free. Very common adapter on North American equipment.
Installation: SAE ORB has the same thread as JIC at some sizes. Do not assume they're interchangeable. The seal mechanisms are completely different (flare vs. O-ring).
Pressure: Excellent combination for high-pressure systems. Both sides are high-rated.
Common mistake: Confusing SAE ORB port threads with JIC threads. Same thread pitch, different seal method. Connecting JIC to an ORB port without the proper adapter means no O-ring seal, which leaks.
JIC to DIN Uncommon
Available sizes: -6, -8, -10, -12, -16
Shapes: straight, 90-degree
Seal: JIC side: 37-degree flare with UNF threads. DIN side: 24-degree bite-type with metric threads. These are cross-continent adapters, common on mixed-origin equipment.
Installation: DIN metric threads are close to but NOT the same as UNF threads. Never force a metric fitting into a UNF port.
Pressure: Both standards are high-pressure rated. The DIN side depends on proper ferrule pre-set.
Common mistake: Thread misidentification between metric DIN threads and SAE/UNF threads. Use a thread pitch gauge to verify before connection.
JIC to JIS Uncommon
Available sizes: -4, -6, -8, -12
Shapes: straight
Seal: JIC: 37-degree flare with UNF threads. JIS: 30-degree or 60-degree cone with metric threads. Despite similar appearances, the seat angles are incompatible.
Installation: JIC and JIS fittings can sometimes thread together because metric and UNF sizes are close. This is extremely dangerous. The different seat angles create a leak path that may hold at low pressure but blow out at working pressure.
Pressure: Use purpose-built cross-standard adapters only. Do not mix native JIC and JIS fittings.
Common mistake: Forcing JIC fittings into JIS ports (or vice versa) because they 'almost' thread in. The seat angle mismatch causes leaks or blowout.
NPT to BSP
Available sizes: -4, -6, -8, -12, -16
Shapes: straight, 90-degree
Seal: NPT side: taper thread with PTFE tape. BSP side: parallel (bonded seal) or taper (tape). Both are thread-sealed standards but with different thread angles (60-degree vs 55-degree).
Installation: NPT and BSP threads are NOT interchangeable despite similar appearances. NPT has a 60-degree thread angle, BSP has 55 degrees. They may thread together for a few turns but will leak.
Pressure: Both are medium-pressure standards. This combination is limited by whichever side has the lower rating at the given size.
Common mistake: Assuming NPT and BSP are the same because they 'fit.' They thread together loosely at small sizes but the thread angle mismatch prevents a proper seal.
NPT to ORFS
Available sizes: -4, -6, -8, -10, -12, -16
Shapes: straight, 90-degree
Seal: NPT side: tape on taper threads. ORFS side: O-ring face seal, no sealant. Common when transitioning from pipe-threaded components to tube-connected components.
Installation: The NPT side is the weak link in this combination. ORFS is designed for zero-leak, but the NPT side depends on tape quality and proper tightening.
Pressure: Limited by NPT side pressure rating.
Common mistake: Using this adapter in high-vibration applications where the NPT side can loosen over time. Consider replacing the NPT port with SAE ORB if possible.
NPT to SAE ORB
Available sizes: -4, -6, -8, -10, -12, -16
Shapes: straight, 90-degree
Seal: NPT side: tape on taper. SAE ORB side: O-ring seal. Very common adapter for converting pipe-thread ports to O-ring sealed connections.
Installation: Same as NPT to ORFS. The NPT side is the maintenance point. SAE ORB side is virtually leak-free.
Pressure: Limited by NPT side.
Common mistake: Not replacing the O-ring on the SAE ORB side after disassembly. The O-ring is cheap and should be replaced every time.
ORFS to SAE ORB
Available sizes: -4, -6, -8, -10, -12, -16
Shapes: straight, 90-degree
Seal: Both sides are O-ring sealed. This is the most leak-proof adapter combination available. No sealant needed on either side.
Installation: Ensure both O-rings are in good condition and properly seated. This is a premium connection.
Pressure: Both standards have the highest pressure ratings. Excellent for critical systems.
Common mistake: Only replacing one O-ring during maintenance. Replace both.
BSP to DIN
Available sizes: -6, -8, -10, -12, -16
Shapes: straight, 90-degree
Seal: BSP side: bonded seal (BSPP) or tape (BSPT). DIN side: bite-type compression, no sealant. Common on European and Asian mixed-standard equipment.
Installation: Both standards use metric-area thread pitches. Verify thread pitch with a gauge, not by feel.
Pressure: Good combination for medium-high pressure European systems.
Common mistake: Mixing up BSP and DIN metric thread pitches. They are different standards with different thread geometry.
BSP to JIS
Available sizes: -4, -6, -8, -12
Shapes: straight
Seal: BSP: parallel (bonded seal) or taper (tape). JIS: 30-degree or 60-degree cone with metric threads. Common on Japanese equipment with British-origin hydraulic systems.
Installation: Thread pitch overlap between BSP and JIS can cause misidentification. Always verify with a thread gauge.
Pressure: Medium-high. Both are robust standards.
Common mistake: Assuming JIS metric threads are the same as BSP. They have different origins and different sealing surfaces.
Cross-Standard Size Equivalents
Hydraulic fitting sizes are referenced by dash number. The same flow size can have different thread dimensions across standards. This table shows equivalent sizes for the most common dash numbers.
| Dash | JIC Thread | NPT | BSP | ORFS Thread | DIN Thread |
|---|---|---|---|---|---|
| -24 | 1-7/8-12 UN | 1-1/2" | 1-1/2" | 2-12 UN | M52x2 |
| -20 | 1-5/8-12 UN | 1-1/4" | 1-1/4" | 1-11/16-12 UN | M42x2 |
| -16 | 1-5/16-12 UN | 1" | 1" | 1-7/16-12 UN | M36x2 |
| -12 | 1-1/16-12 UN | 3/4" | 3/4" | 1-3/16-12 UN | M30x2 |
| -10 | 7/8-14 UNF | 3/4" | 1/2" | 1-14 UNS | M24x1.5 |
| -8 | 3/4-16 UNF | 1/2" | 1/2" | 13/16-16 UN | M18x1.5 |
| -6 | 9/16-18 UNF | 3/8" | 3/8" | 11/16-16 UN | M16x1.5 |
| -4 | 7/16-20 UNF | 1/4" | 1/4" | 9/16-18 UNF | M12x1.5 |
Hydraulic Adapter Questions
How do I know which hydraulic adapter I need?
Identify the fitting standard on each side (JIC, NPT, BSP, ORFS, DIN, JIS, or SAE ORB), then determine the size (dash number or nominal pipe size) and gender (male or female) of each connection. The adapter must match both sides exactly.
Can I connect JIC to NPT fittings?
Yes. JIC to NPT adapters are among the most common hydraulic adapters. The JIC side seals with a 37-degree metal flare (no sealant), while the NPT side seals on tapered threads with PTFE tape. Available in straight, 90-degree, and 45-degree configurations.
What is the difference between BSPP and BSPT?
BSPP (BSP Parallel) has straight threads and seals with a bonded washer or O-ring on a flat face. BSPT (BSP Taper) has tapered threads and seals by thread interference, like NPT. They look identical but require different adapters. Using the wrong type will leak under pressure.
What is the maximum pressure for a hydraulic adapter?
The maximum working pressure of an adapter is determined by the weaker of the two standards and the size. Smaller sizes generally have higher pressure ratings. ORFS and SAE ORB have the highest ratings (up to 6,000 PSI), while NPT has the lowest (typically 1,000 to 3,000 PSI depending on size).